Indoor unit and air conditioner

ABSTRACT

An indoor unit is equipped with a housing having an inlet opening and an outlet opening, a propeller fan disposed in an air passage interconnecting the inlet opening and the outlet opening, a heat exchanger disposed downstream from the propeller fan, and a lateral airflow direction changing plate that is disposed downstream from the heat exchanger and that changes an airflow direction laterally. The heat exchanger is a fin-and-tube type heat exchanger equipped with a plurality of fins and a plurality of heat transfer tubes passing through the fins. The lateral airflow direction plate has slits in an airflow downstream region that is downstream from the heat transfer tubes.

TECHNICAL FIELD

The present disclosure relates to an indoor unit and an air conditioner.

BACKGROUND ART

An air conditioner is equipped with airflow direction changing plates for changing direction of blown air flowing out from an indoor unit. For example, in Patent Literature 1, a lateral airflow direction changing plate is proposed that has multiple slits formed thinly in a direction of airflow in an intermediate region and excluding an upstream end region and an airflow downstream end region of airflow.

CITATION LIST Patent Literature

Patent Literature 1: Unexamined Japanese Patent Application Kokai Publication No. 2008-80839

SUMMARY OF INVENTION Technical Problem

The lateral airflow direction changing plate is sometimes disposed in the downstream vicinity of a fin-and-tube type heat exchanger. In this case, the air reaches the lateral airflow direction changing plate in a state in which both a temperature distribution and an absolute humidity distribution of the air remain non-uniform, and such operation suffers from the occurrence of condensation on the lateral airflow direction changing plate.

In order to solve such a problem, an object of the present disclosure is to provide an indoor unit and an air conditioner that are equipped with an airflow direction changing plate on which condensation tends not to occur.

Solution to Problem

In order to attain the aforementioned objective, an indoor unit according to the present disclosure includes:

an air blower disposed in an air passage;

a heat exchanger disposed downstream from the air blower and including a plurality of fins and a heat transfer tube passing through the fins; and

an airflow direction changing plate to change an airflow direction, the airflow direction changing plate being disposed downstream from the heat exchanger and having an opening portion in an airflow downstream region that is downstream from the heat transfer tube.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the airflow direction changing plate has an opening portion in the airflow downstream region from the heat transfer tube. Therefore, condensation on the airflow direction changing plate tends not to occur.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional drawing as viewed from a side face of an indoor unit according to Embodiment 1 of the present disclosure;

FIG. 2A is a perspective view of a lateral airflow direction changing plate according to Embodiment 1;

FIG. 2B is a drawing illustrating arrangement of a heat exchanger and the lateral airflow direction changing plate as viewed at a frontally forward tilt;

FIG. 3A is a side view of the lateral airflow direction changing plate according to Embodiment 1;

FIG. 3B is a drawing for description of change of an opening fraction of slits per unit surface area;

FIG. 4 is a contour diagram (contour drawing) of a numerical analysis illustrating a temperature distribution of air flowing in a periphery of the lateral airflow direction changing plate during cooling;

FIG. 5 is a contour diagram of a numerical analysis illustrating a condensation speed distribution of a lateral airflow direction changing plate surface in the case of the air temperature distribution conditions illustrated in FIG. 4;

FIG. 6 is a side view of a lateral airflow direction changing plate according to Embodiment 2 of the present disclosure;

FIG. 7 is a side view of a lateral airflow direction changing plate according to Embodiment 3 of the present disclosure;

FIG. 8 is a side view of a lateral airflow direction changing plate according to Embodiment 4 of the present disclosure;

FIG. 9 is a side view of a lateral airflow direction changing plate according to Embodiment 5 of the present disclosure;

FIG. 10A is a drawing illustrating an example of a cross-sectional shape of an opening portion of the lateral airflow direction changing plate surface;

FIG. 10B is a drawing illustrating another example of a cross-sectional shape of an opening portion of the lateral airflow direction changing plate surface;

FIG. 10C is a drawing illustrating yet another example of a cross-sectional shape of an opening portion of the lateral airflow direction changing plate surface;

FIG. 10D is a drawing illustrating yet even another example of a cross-sectional shape of an opening portion of the lateral airflow direction changing plate surface; and

FIG. 11 is a drawing of an air conditioner according to Embodiment 1.

DESCRIPTION OF EMBODIMENTS Embodiment 1

An indoor unit 100 according to Embodiment 1 of the present disclosure is described with reference to the drawings. Each of the drawings is schematic, and thus components are not limited to the shapes and sizes illustrated in the drawings. In the drawings, components that are the same or equivalent are assigned the same reference sign. The present disclosure relates to suppression of condensation, and thus operation during cooling is assumed and described unless otherwise noted.

The indoor unit 100 according to Embodiment 1, as illustrated in FIG. 11, is connected to an outdoor unit 102 via refrigerant tubes 101, and these components together make up an air conditioner 110.

As illustrated in FIG. 1, an inlet opening 2 that sucks in air is arranged in an upper face of a housing 1 of the indoor unit 100, and an outlet opening 3 from which air blows out is arranged in a lower face and a lower portion of a front face. Furthermore, FIG. 1 is a cross-sectional drawing as viewed from the side face of the indoor unit 100, the left direction of the drawing is the indoor direction in which air is sent and is also termed “front (frontward)”, and the right direction of the drawing is the direction to the wall for attachment of the indoor unit 100 and is also termed “rear (rearward)”. The upward direction in the drawing is also termed “up (above)”, and the downward direction is also termed “down (below)”.

In an air passage interconnecting the inlet opening 2 and the outlet opening 3 are arranged: a pushing-in type propeller fan 4 for sucking in indoor air from the inlet opening 2 and sending out the air to a heat exchanger side, a heat exchanger 50 positioned in an airflow downstream direction that is downstream from the propeller fan 4 and positioned in an airflow upstream direction that is upstream from the outlet opening 3, and a drain pan 6, disposed below the heat exchanger 50, for receiving and discharging water that is generated due to condensation by the heat exchanger 50. Further, in the present disclosure, “airflow” is taken to mean the flow of air produced by the propeller fan 4. The propeller fan 4 is one example of an air blower.

The heat exchanger 50 heats or cools the air blown by the propeller fan 4. Specifically, the heat exchanger 50 includes a forward-tilted portion 50 a that is tilted forward, a rearward-tilted portion 50 b that is tilted rearward and positioned opposingly behind the forward-tilted portion 50 a, a forward-tilted portion 50 c that is tilted forward and positioned opposingly behind the rearward-tilted portion 50 b, and a rearward-tilted portion 50 d that is tilted rearward and positioned opposingly behind the forward-tilted portion 50 c; and these components are arranged in a W-shaped configuration.

The forward-tilted portion 50 a, the rearward-tilted portion 50 b, the forward-tilted portion 50 c, and the rearward-tilted portion 50 d each include flat plate-like fins 51 arranged in a row and heat transfer tubes 52 passing through the fins 51 to form a fin-and-tube type heat exchanger unit. By flow of a heat transfer medium within the heat transfer tubes 52, by allowing the cold temperature of the heat transfer medium during cooling to transfer heat to the fins 51 that have a large surface area, and by use of the fins as heat exchange plates, the fin-and-tube type heat exchanger efficiency performs cooling of the air. The fins 51 are arranged parallel to a direction of flow of air so as not to impede the flow of air, and the heat transfer tubes 52 are arranged extending in a direction orthogonal to the direction of flow of air.

In the outlet opening 3 of the housing 1, a frontward positioned front-side vertical airflow direction changing plate 7 and a rearward positioned rear-side vertical airflow direction changing plate 8 are arranged, and each of these plates can change vertically the airflow direction of the air.

The bottom-side lateral airflow direction changing plate 9 is arranged below the front-side vertical airflow direction changing plate 7. The bottom-side lateral airflow direction changing plate 9 can change the lateral airflow direction of the air subjected to heat exchange by the rearward-tilted portion 50 b, the forward-tilted portion 50 c, and the rearward-tilted portion 50 d. Moreover, multiple top-side lateral airflow direction changing plates 20 are arranged downstream from the forward-tilted portion 50 a. The top-side lateral airflow direction changing plates 20 can laterally change the airflow direction of the air subject to heat exchange by the forward-tilted portion 50 a.

As illustrated in FIG. 2A, cylindrically shaped attaching parts 15 of the top-side lateral airflow direction changing plates 20 are supported by supporting parts 16. The supporting parts 16 are fixed to a fixing part 10 fixed to the drain pan 6. The drain pan 6 is attached to the housing 1 of the indoor unit 100. The top-side lateral airflow direction changing plates 20 are rotatably supported with respect to the supporting parts 16 so as to be capable of clockwise or counter-clockwise rotation around, as central axes, cylinder axes of the attaching parts 15.

Each of the top-side lateral airflow direction changing plates 20 is connected to a single connector 12 via a respective fixing implement 14, so that all of the top-side lateral airflow direction changing plates 20 are interlocked with the connector 12 to enable simultaneous change of direction. Specifically, upon movement of the connector 12 in the rightward direction of FIG. 2A, all of the top-side lateral airflow direction changing plates 20 rotate in the counter-clockwise direction around, as the central axis of rotation, the cylinder axis of the respective attaching part 15. In doing so, the flow of air subjected to heat exchange by the forward-tilted portion 50 a changes become directed rightward. Conversely, upon movement of the connector 12 in the leftward direction of FIG. 2A, all of the top-side lateral airflow direction changing plates 20 rotate in the clockwise direction around, as the central axis of rotation, the cylinder axis of the respective attaching part 15. In doing so, the flow of air changes to become directed leftward. The lateral flow direction of air can be adjusted in this manner.

As illustrated in FIG. 2B, the top-side lateral airflow direction changing plates 20 are oriented in the same direction as that of the fins 51, and are disposed at downstream locations of the air passing through gaps between the fins 51. The spacing between the fins 51 is narrow, such as about 1 mm. Therefore, all air passing between the fins 51 undergoes an effect of cooling by the fins 51, and thus temperature imbalances are small. That is to say, temperature differences are small between an airflow 46 passing through the vicinity of the top-side lateral airflow direction changing plate 20 and an airflow 44 passing outside the vicinity of the top-side lateral airflow direction changing plate 20. Thus, a side-direction arrangement position of the top-side lateral airflow direction changing plate 20 in FIG. 2B may be freely selected as long as the arrangement position is downstream from the air passing within an overall region formed by the fins 51.

Although operation of the indoor unit 100 is performed by use of a device such as an operating remote controller to start an operation, stop an operation, and set parameters such as temperature, air flow rate, and airflow direction, the control system technology is the same as that of a conventional control system. Moreover, the technology of the outdoor unit 102 that is used for heat exchange is the same as that of a conventional outdoor unit.

As illustrated in FIG. 3A, each of the top-side lateral airflow direction changing plates 20 has, in a region of relatively low air temperature in comparison to the surroundings in the airflow downstream from the heat transfer tube 52, two openings 21 a and 21 b having gradually decreasing widths from the air flow upstream to the downstream. Hereinafter, in accordance with these shapes, the openings 21 a and 21 b are referred to as the slits 21 a and 21 b. Further, the upper-right direction in FIG. 3A is the airflow upstream direction, and the lower-left direction is the airflow downstream direction.

The expression “airflow downstream from the heat transfer tube 52” means the region at the downstream side through which air flows at the periphery of the heat transfer tube 52. Due to the presence of multiple heat transfer tubes 52, multiple airflow downstreams exist. The term “slit” means an opening having a long-narrow shape. The term “opening portion” means a hole, notch, or the like passing from one surface to the other surface of the top-side lateral airflow direction changing plate 20. The expression “opening having gradually decreasing width” means that a fraction of an opening surface area of the openings 21 a and 21 b per a certain unit surface area of the top-side lateral airflow direction changing plate 20 gradually decreases.

For example, as illustrated in FIG. 3B, four virtual rectangles 28 a, 28 b, 28 c, and 28 d are considered as indicated by short-dashed lines overlapping the opening of the slit 21 b. These are rectangles of the same surface area disposed adjacent to each other, in order, from the air flow upstream side to the downstream side of the slit 21 b. Firstly, the virtual rectangle 28 a is disposed such that the fraction of the opening of the slit 21 b included in the virtual rectangle 28 a is largest. Next, adjacent to the virtual rectangle 28 a, the virtual rectangle 28 b is disposed such that the fraction of the opening of the slit 21 b included in the virtual rectangle 28 b is largest. In the same manner, the virtual rectangle 28 c and the virtual rectangle 28 d are disposed in order. Due to arrangement in this manner, the surface area fraction of the opening of the slit 21 b occupied in the surface area of the virtual rectangle 28 a is largest, the opening fraction of the slit 21 b occupied in the surface area of the virtual rectangle 28 b is next largest, the opening fraction of the slit 21 b occupied in the surface area of the virtual rectangle 28 c is next largest, and the smallest opening fraction is the opening fraction of the slit 21 b occupied by the virtual rectangle 28 d most at the downstream side. These relationships are similar for slit 21 a.

For description of operation of such slits 21 a and 21 b, a mechanism is described by which condensation occurs in an example of a lateral airflow direction changing plate 40 of the conventional technology that is not equipped with the slits 21 a and 21 b with reference to FIGS. 4 and 5.

In FIG. 4, intermediate temperature regions 41 filled with hatching are regions through which air flows of a temperature that is between temperatures of a low temperature region 43 through which air flows that is cooled by the heat transfer tube 52 and a high temperature region 42 through which air flows that is near room temperature. The long-dashed line indicates an isothermal line of the boundary between the low temperature region 43 and the intermediate temperature region 41. The short-dashed line indicates an isothermal line of the boundary between the high temperature region 42 and the intermediate temperature region 41. The long-dashed line is thus an isothermal line of lower temperature in comparison to the short-dashed line. Curvature of the flow of air in this manner is used because the drain pan 6 is disposed below the heat transfer tubes 52 and the flow of air there is blocked.

As illustrated in FIG. 4, the air temperature of the intermediate temperature region 41 that is downstream in the airflow from the heat transfer tubes 52 is relatively low in comparison to the air temperature of the high temperature region 42 of air that flows by passing through the middle between the heat transfer tubes 52. The air of this intermediate temperature region 41 touches the surfaces of the lateral airflow direction changing plate 40, and thus this air is cooled by the surfaces of the lateral airflow direction changing plate 40. Within the lateral airflow direction changing plate 40, heat conduction occurs and the low temperature portion reaches the region of the lateral airflow direction changing plate 40 through which the air of the high temperature region 42 passes, and the surface temperature of this region declines. Condensation occurs when the surface temperature of the region through which the air of the high temperature region 42 passes is less than or equal to a dew point temperature of air of the high temperature region 42.

In FIG. 5, the hatched portion is a region in which condensation speed is greater than or equal to zero, that is to say, is a condensation region 47 in which condensation occurs. As illustrated in FIG. 5, condensation does not occur on the surface of the lateral airflow direction changing plate 40 in a vicinity of passage of a flowline 45 having, as an originating point, an airflow back portion the heat transfer tube 52, but rather condensation occurs in a region at a periphery of such vicinity.

As may be understood from FIGS. 4 and 5, condensation on the lateral airflow direction changing plate 40 is caused by: the air that is cooled by the heat transfer tube 52 and is at relatively low temperature in comparison to the periphery contacting the lateral airflow direction changing plate 40 and being partially cooled by the lateral airflow direction changing plate 40, and the region cooled by heat conduction within the lateral airflow direction changing plate 40 spreading so that there is a portion where the air contacting the surface is less than or equal to the dew point. On the basis of the aforementioned condensation mechanism, avoiding partial cooling of the lateral air direction charging plate 40, that is, as much as possible avoiding contact of the lateral air direction charging plate 40 with the air cooling by the heat transfer tube 52, is understood to be preferable for suppressing the condensation on the lateral airflow direction changing plate 40.

Therefore, in the present disclosure as illustrated in FIG. 3A, the slits 21 a and 21 b are arranged in the region through which flows air of relatively low temperature of the top-side lateral airflow direction changing plate 20 located in the airflow downstream from the heat transfer tube 52. Due to such configuration, the surface area where the relatively low-temperature air contacts the top-side lateral airflow direction changing plate 20 can be decreased. Furthermore, the region of transmission of heat becomes smaller, and a heat conduction suppression effect can be anticipated.

Moreover, as illustrated in FIG. 5, the air cooled by the heat exchanger 50 gradually mixes with relatively warm air of the periphery from the airflow upstream to the downstream position, and the air temperature distribution is equalized so that the condensation region narrows with distance downstream. Width of the slits gradually decrease with distance from the airflow upstream to the downstream as in the slits 21 a and 21 b, and thus the lowering in airflow direction change performance can be suppressed while achieving the condensation prevention effect.

Due to configuration in this manner, the risk of the occurrence of condensation on the top-side lateral airflow direction changing plate 20 can be decreased, and even if condensation occurs, a decrease in the condensation amount can be achieved.

According to Embodiment 1 as described above, the top-side lateral airflow direction changing plate 20 has the slits 21 a and 21 b in which slit width gradually decreases from the air flow upstream to the downstream, of the rear portion of the heat transfer tube 52, in the region contacted by air of relatively low temperature in comparison to the periphery. Due to such configuration, an indoor unit 100 can be provided for which condensation tends not to occur even when the top-side lateral airflow direction changing plate 20 is positioned in the downstream vicinity of the fin-and-tube type heat exchanger 50.

Although the shapes of the slits 21 a and 21 b are determined so as to match the distribution of air temperature as described above, in the case in which the shape of the distribution of air temperature differs in accordance with the position of the top-side lateral airflow direction changing plate 20, the shapes of the slits 21 a and 21 b may differ among the top-side lateral airflow direction changing plates 20. Moreover, although there are two slits 21 a and 21 b in Embodiment 1, the number of the slits may be freely determined to match the distribution state of the air temperature.

Moreover, although the bottom-side lateral airflow direction changing plate 9 in Embodiment 1 is disposed at the downstream side of the heat transfer tube 52 of the rearward-tilted portion 50 b, the forward-tilted portion 50 c, and the rearward-tilted portion 50 d, the distance from the heat transfer tube 52 is great, and relatively low temperature air and warm air may intermix, and thus condensation tends not to be locally generated. Although the slits are thus not arranged in the bottom-side lateral airflow direction changing plate 9, in the case in which a distribution of air temperature arises due to the arrangement relationship between the heat transfer tubes 52 and the bottom-side lateral airflow direction changing plate 9 such that condensation easily occurs, slits can be arranged also in the bottom-side lateral airflow direction changing plate 9.

Embodiment 2

Embodiment 2 is an example of arrangement of, rather than the slits 21 a and 21 b of Embodiment 1, notches 22 a and 22 b having a shape in which the upstream end of the slit opens. The notches 22 a and 22 b are examples of openings similar to the slits 21 a and 21 b. FIG. 6 is a view of a top-side lateral airflow direction changing plate 20 a according to Embodiment 2 as viewed from the side.

As illustrated in FIG. 6, the top-side lateral airflow direction changing plate 20 a has two notches 22 a and 22 b that decreases gradually in notch width from the airflow upstream to the downstream in a region, in airflow downstream from the heat transfer tube 52, contacted by air of relatively low temperature in comparison to the periphery. The term “notch” means an opening portion that opens up to an edge surface of the top-side lateral airflow direction changing plate 20 a. Although the slits 21 a and 21 b in the top-side lateral airflow direction changing plate 20 of Embodiment 1 are through holes that do not open to the end surface, the notches 22 a and 22 b open up to the airflow upstream-side end surface of the top-side lateral airflow direction changing plate 20 a. The gradual decrease in the width of the notches means that the fraction of opening surface area of the notches 22 a and 22 b per virtual unit surface area gradually decreases toward the downstream side. Further, also as described in Embodiment 1, the number of the notches is freely selected, meaning that the number is not limited to two, and may be one or three or more.

Due to configuration in this manner, cooling of the top-side lateral airflow direction changing plate 20 a during cooling operation decreases, and the heat conduction within the top-side lateral airflow direction changing plate 20 a can be suppressed. In comparison to the conventional technology, the risk of condensation can thus be decreased, and even if condensation occurs, a decrease in the condensation amount can be achieved.

Further, in a manner similar to that of Embodiment 1, width of the notches 22 a and 22 b gradually decreases from the air flow upstream side to the downstream side, and thus while decreasing the risk of condensation, this has the effect of suppressing the lowering of airflow direction change performance.

Moreover, although the upstream end of the top-side lateral airflow direction changing plate 20 a is the location at which condensation tends to occur due to the air temperature distribution being the most equalized, notching of the upstream end has the effect of decreasing the risk of condensation.

Embodiment 3

Embodiment 3 is an example of an arrangement of, rather than the slits 21 a and 21 b of Embodiment 1, multiple through holes 23 having different diameters in the airflow downstream regions of the heat transfer tubes 52. The through holes 23 are examples of openings. FIG. 7 is a view as seen from the side face of a top-side lateral airflow direction changing plate 20 b according to Embodiment 3.

As illustrated in FIG. 7, the top-side lateral airflow direction changing plate 20 b has multiple circular through holes 23 of gradually decreasing diameters from the airflow upstream to the downstream in the regions, of the airflow downstream from the heat transfer tubes 52, where air flows of relatively low temperature in comparison to the periphery. The gradual decrease in diameter of the circular through holes 23 means that the opening fraction of the through holes 23 per virtual unit surface area gradually decreases toward the downstream side. Furthermore, although the circular through holes 23 are disposed in two rows, the number of rows of the arranged through holes in this case is also freely selected, meaning the number is not limited to two rows, and may be one row, or three or more rows.

Due to configuration in this manner, cooling of the top-side lateral airflow direction changing plate 20 b decreases during the cooling operation, and heat conduction within the top-side lateral airflow direction changing plate 20 b can be suppressed. Thus, the risk of condensation can be decreased in comparison to the conventional technology, and even if condensation occurs, the amount of condensation can be decreased.

Furthermore, the opening fraction of the through holes 23 gradually decreases, in a manner similar to that of Embodiment 1, from the airflow upstream to the downstream, and thus while decreasing the risk of condensation, this has the effect of suppressing the lowering of the airflow direction change performance.

Embodiment 4

Embodiment 4 is an example of arrangement of, in place of the slits 21 a and 21 b of Embodiment 1, multiple circular through holes 24, each of the same diameter, in the airflow downstream region from the heat transfer tubes 52. FIG. 8 is a view from the side face of the top-side lateral airflow direction changing plate 20 c according to Embodiment 4.

As illustrated in FIG. 8, the top-side lateral airflow direction changing plate 20 c has multiple circular through holes 24 for which a distribution count gradually decreases from the airflow upstream to the downstream in the regions, in the airflow downstream from the heat transfer tubes 52, where air flows of relatively low temperature in comparison to the periphery. Although the diameters of the multiply arranged through holes 24 are the same, the number (distribution fraction) decreases with distance in the downstream direction. That is to say, the opening fraction of the through holes 24 per virtual unit surface area gradually decreases toward the downstream side. Further, although the circular through holes 24 are arranged in two rows, the number of rows is not limited to two rows, and the arrangement may be in one row or three or more rows.

Due to configuration in this manner, the cooling of the top-side lateral airflow direction changing plate 20 c during the cooling operation may decrease, and heat conduction within the top-side lateral airflow direction changing plate 20 c can be suppressed. The risk of condensation can thus be decreased in comparison to the conventional technology, and even if condensation occurs, a decrease in the condensation amount can be achieved.

Furthermore, the distribution fraction of the number of the through holes 24 gradually decreases from the airflow stream to the downstream, and thus in a manner similar to that of Embodiment 1, while decreasing the risk of condensation, this has the effect of suppressing the lowering of the airflow direction change performance.

Embodiment 5

Embodiment 5 is an example in which through holes 25 are disposed over an entire surface rather than as the slits 21 a and 21 b of Embodiment 1. FIG. 9 is a view from the side of a top-side lateral airflow direction changing plate 20 d according to Embodiment 5.

As illustrated in FIG. 9, the top-side lateral airflow direction changing plate 20 d has square-shaped through holes 25 evenly over the entire region thereof, forming a mesh pattern. Further, the shape of the through holes 25 is not limited to a square, and the shape may be freely selected. Also, the number of such holes can be freely selected. Further, although the arrangement density of the through holes 25 can be uniform overall as shown in FIG. 9, the opening density of the through holes 25 preferably decreases gradually from the upstream side to the downstream side. Reason being, even when the airflow is irregular, since the air of the upstream side is cooled more than the air of the downstream side, it is more effective for prevention of condensation to increase the opening density at the upstream side.

Due to configuration in this manner, even when the air temperature distribution and the absolute humidity distribution are irregular after passage of air through the heat exchanger 50, an effect of preventing condensation on the top-side lateral airflow direction changing plate 20 d can be achieved. That is, even when the flow of cooled air changes irregularly, the possibility of condensation on the top-side lateral airflow direction changing plate 20 d can be decreased. Further, due to making the opening density of the through holes 25 uniform over the entire top-side lateral airflow direction changing plate 20 d, whatever the air temperature distribution and the absolute humidity distribution after passage of air through the heat exchanger 50, such configuration enables the achievement of an effect that is prevention of condensation on the top-side lateral airflow direction changing plate 20 d.

Modified Example 1

Although examples are indicated in which the openings are formed in the lateral airflow direction changing plate in the embodiments, the direction of change of the airflow is not limited to any particular direction. The airflow direction changing plate of the present disclosure may change airflow in the lateral direction, or may change airflow in the forward-rearward direction. The present disclosure is applicable as long as an airflow direction changing plate is disposed downstream from the fin-and-tube type heat exchanger.

Modified Example 2

Although an edge surface shape of the opening portion is not particularly limited, the opening portion preferably has a shape that does not make the flow of air passing through the opening portion unsteady. Although the opening portion may have a right-angled end surface in the surface of the top-side lateral airflow direction changing plate 20 as illustrated in FIG. 10A, from the standpoint of not making the passage of air unsteady, the opening portion preferably has an end surface that is bowed or sloped as illustrated in FIGS. 10B to 10D. FIG. 10B is an example of an end surface shape that is smoothly bowed, FIG. 10C is an example of an end surface shape that is sloped, and FIG. 10D is an example of an end surface shape in which faces are formed tilted from both surface sides. Furthermore, the shape of the end surface may be different for the upstream side versus the downstream side.

Modified Example 3

The propeller fan is used as the air blower in Embodiments 1 to 5. The type of the air blower is not limited to this type. For example, a crossflow fan may be used. Moreover, the propeller fan may be an axial flow propeller fan or a diagonal flow propeller fan. Alternatively, a centrifugal fan may be used.

The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

INDUSTRIAL APPLICABILITY

The present disclosure can be used with advantage for an indoor unit of an air conditioner.

REFERENCE SIGNS LIST

-   1 Housing -   2 Inlet opening -   3

Outlet opening

-   4 Propeller fan -   6 Drain pan -   7 Front-side vertical airflow direction changing plate -   8 Rear-side vertical airflow direction changing plate -   9 Bottom-side lateral airflow direction changing plate -   10 Fixing part -   12 Connector -   14 Fixing implement -   15 Attaching part -   16 Supporting part -   20, 20 a, 20 b, 20 c, 20 d Top-side lateral airflow direction     changing plate -   21 a, 21 b Slit -   22 a, 22 b Notch -   23, 24, 25 Through hole -   28 a, 28 b, 28 c, 28 d Virtual rectangle -   31 Dust collection filter -   32 Filter-fixing implement -   40 Lateral airflow direction changing plate -   41 Intermediate temperature region -   42 High temperature region -   43 Low temperature region -   44 Airflow -   45 Flowline -   46 Airflow -   47 Condensation region -   50 Heat exchanger -   50 a Forward-tilted portion -   50 b Rearward-tilted portion -   50 c Forward-tilted portion -   50 d Rearward-tilted portion -   51 Fin -   52 Heat transfer tube -   100 Indoor unit -   101 Refrigerant tube -   102 Outdoor unit -   110 Air conditioner 

1. An indoor unit comprising: an air blower disposed in an air passage; a heat exchanger disposed downstream from the air blower and including a plurality of fins and a heat transfer tube passing through the fins; and an airflow direction changing plate to change an airflow direction, the airflow direction changing plate being disposed downstream from the heat exchanger and having an opening portion in an airflow downstream region that is downstream from the heat transfer tube; wherein an opening fraction of the opening portion gradually decreases from an airflow upstream to an airflow downstream.
 2. (canceled)
 3. An indoor unit comprising: an air blower disposed in an air passage; a heat exchanger disposed downstream from the air blower and including a plurality of fins and a heat transfer tube passing through the fins; and an airflow direction changing plate to change airflow direction, the airflow direction changing plate being disposed downstream from the heat exchanger and having an opening portion in an airflow downstream region that is downstream from the heat transfer tube; wherein the opening portion includes a slit extending from an airflow upstream to an airflow downstream of the airflow direction changing plate, and an airflow upstream side of the slit has an opened notch shape.
 4. (canceled)
 5. The indoor unit according to claim 1, wherein the opening portion includes a plurality of through holes, each through hole having a diameter that gradually decreases from an airflow upstream to an airflow downstream of the airflow direction changing plate.
 6. The indoor unit according to claim 1, wherein the opening portion is disposed in an entire region of the airflow direction changing plate and includes a plurality of through holes with an opening density that gradually decreases from an airflow upstream to an airflow downstream of the airflow direction changing plate.
 7. (canceled)
 8. The indoor unit according to claim 1, wherein the air blower includes a propeller fan.
 9. An air conditioner comprising the indoor unit according to claim
 1. 10. The indoor unit according to claim 1, wherein the opening portion includes a slit having a width that gradually decreases from an airflow upstream to an airflow downstream of the airflow direction changing plate.
 11. The indoor unit according to claim 1, wherein the opening portion includes a plurality of through holes for which a distribution count gradually decreases from an airflow upstream to an airflow downstream of the airflow direction changing plate.
 12. The indoor unit according to claim 5, wherein the opening portion includes a plurality of through holes for which a distribution count gradually decreases from an airflow upstream to an airflow downstream of the airflow direction changing plate. 